Spark-plug



E. H. MELENDY.

SPARK PLUG.

APPLICATION FILED SEPT.

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26 /l// l'// 2 7 25 f I /4 I /7 I' I I I I I I I I I /J I I I I I I I I I UNITED STATES PATENT oFFicl-.

SPARK-PLUG.

Specicaton of Letters Patent. I

Paten-teu May io, ieai.

Application filed September 21, 1917. Serial No. 192,562.

To all whom t may concern:

Be it known that I, EARL H. MELENDY, a citizen of the United States, residing at Shellrock, in the county of Butler, State of Iowa, have invented certain new and useful Improvements in Spark-Plugs; and I do hereby declare the following to be a full,

clear, and exact description of the invention, such as will enable others skilled in the art to which is appertains to make and use the same.

This invention relates to spark plugs and it has for its object to provide a structure wherein the porcelain with its contained electrode may be reversed in the sleeve of the plug to interchangeably position the opposite ends of the electrode with respect to the sleeve carrying electrode, without disassembling or in anywise modifying the relations of the porcelain and its electrode.

In the drawing:

Figure 1 is an elevation of a spark plug made in accordance with my invention, a portion of the cylinder being shown in section.

Fig. 2 is a vertical longitudinal sectional rview through the spark plug.

Referring particularly to the accompanying drawing, represents a sleeve which is provided with an externally threaded portion for engagement in the cylinder 11, said threaded portion being represented at 12. On the lower end of the threaded portion there is formed a downwardly and inwardly extending sparking finger or electrode 13, and in the upper end of the sleeve there is formed a shoulder 14. Intermediate the length of the outer face of the sleeve there are formed the wrench engaging faces whereby the sleeve can be easily and quickly engaged in the cylinder or removed therefrom. Disposed vertically through the upper end of the sleeve is a porcelain stem 16, the same tapering toward both ends and having a central circumferential flange or collar 17 which rests on the shoulder 14. Extending longitudinally through the porcelain stem is an electrode forming metal rod 18,- the lower end of which is formed with a tapering extension 19 which is disposed in proper relation to the sleeve carried electrode 13 to permit a spark to jump therebetween. The portion of the metal rod which projects beyond the lower end of the porcelain stem is externally threaded to receive therein the washer 20 and the nut 21. The upper end of the metal rod also extends beyond the upper end of the porcelain stem and is externally threaded to receive therein the washer 22 and the nut 23, the same forming the terminal post for the wire 24. A cap nut 25 is screwed on the upper end of the sleeve 10 and is formed with a central open'- ing 26 through which the upper portion of the porcelain stem extends.V A washer 27 is disposed on the upper face of the flange or collar 17, and against this washer the said cap nut is screwed.

It will be noted that the upper end of the metal rod is also provided with a reduced extension 28 forming a second sparking terminal.

It will be noted that both ends of the porcelain stem, and the metal rod are exactly alike, whereby said stein is capable of being reversed in the sleeve, to bring either of the extensions ofthe rod into proper relation with the electrode 13. Thus there is provided a readily reversible spark plug porcelain, and one wherein it is not necessary to remove the sleeve of the plug from the cylinder, it being only necessary to remove the cap nut 25, when the porcelain stein and metal rod may be quickly and easily withdrawn and reversed without disassembling them.

What is claimed is:

1. A spark plug comprising a sleeve having an electrode, a porcelain reversibly held in the sleeve and an electrode fixed in the porcelain in position for operative relation to the electrode of the sleeve in both positions of the porcelain.

2. A spark plug comprising a sleeve having an electrode?, a porcelain reversibly held in the sleeve, an electrode carried by the porcelain and projecting from both ends of it in position for interchangeable sparking relation to the electrode of the sleeve as the porcelain is reversed, the extremities of the exposed ends of the ,electrode constituting sparking points and the electrode b etween the sparking points and the porcelain being enlarged and threaded to receive a. clamping nut. y

3. The combination with a spark plug porcelain of an electrode held therein and projecting at both ends therefrom with sparking terminals, the projecting portions being adapted for connection. of a feed wire therewith; said porcelain being shaped for reversible engagement in a spark plug sleeve Wuh said sparking terminas nerehangeably in eopemtve felation to "ehe eeetrede v of @he Sleeven The combnaiom with a spak plug porcelain having a, centml energemem;

engage at either end 2L sleeve seat, of electrode exendmg ongltudmally aheu the porcelana Wlith fas Vgefmmals the same dsanee from the corresponding ends said enargement, said pejectng portions l0 being both adapted for Connection of a feed We therewith?.

Jn testimony :whereof @Hifi my signature in the presence of @We WhA sses.

e MELENDY.

Vfnesses E. TYLER V, A.; 

